1. Field of the Invention
The present invention relates to an aircraft passenger seat swivel assembly to be mounted between an aircraft seat frame and aircraft seat base so as to permit rotation of the aircraft passenger seat when desired, relative to the aircraft seat frame. The swivel assembly also provides a strong, tightly secured, locked engagement therebetween when relative movement of the aircraft passenger seat is not desired.
2. Desciption of the Related Art
The Federal Aviation Administration (FAA) has established very strict regulations for the structures of all aircraft as well as aircraft components, including aircraft passenger seats. Aircraft passenger seats in particular are subjected to a number of different FAA tests designed to assure the aircraft seat will be reasonably safe in a crash scenario, and these tests frequently expose weakness in the structural makeup of the aircraft seat. Because the passenger seats on commercial aircraft are quite basic and contain minimal comfort features, these are not affected by all of the FAA tests for aircraft passenger seats. However, the owners of many private aircraft often specify that passenger seats have additional comfort features such as the ability to swivel and slide. Thus, the field of constructing customized aircraft passenger seats is quite specialized, and is particularly affected by the number and type of tests as prescribed by the Federal Aviation Administration (FAA) to regulate the integrity of aircraft passenger seats. Such field of art is particularly specialized as it relates to custom aircraft seating because of the many additional features often desired in the custom seating.
One feature often requested in customized aircraft passenger seats is the ability to swivel the seat so that it rotates relative to the base. The base of the seat is in turn fixedly secured to the underlying support surface, usually the floor of the aircraft. Although some conventional chairs are built to swivel, that feature is particularly specialized with regard to aircraft seating because in addition to being able to swivel smoothly and comfortably, the seat must also be able to be secured and maintained in place so as to withstand substantial impact forces. Specifically, the swivel assembly of an aircraft seat must undergo certain tests mandated by the FAA and must withstand substantial impact forces during such tests; for which the levels of such tests have recently been increased by the FAA. These recent, very high FAA testing standards are just now beginning to affect the seat manufacturing industry, and consequently the choices available to the consumers of customized aircraft seats, including the swivel assembly for them.
Presently in the art, conventional swivel assemblies for aircraft passenger seats mount the seat frame on a round or ring-shaped platform which has a number of notches formed in and about its exterior perimeter. For such assemblies, a separate lock mechanism is included which is mounted to the seat frame and is used to secure the seat frame in place. In this design, the lock mechanism employed generally incorporates a pin disposed at an end of a biased lever arm which is positioned tangent to the round platform. When disengaged, the lever arm is pulled against its normal bias to release the pin from an engaged orientation. When, however, locking is desired and the lever arm is released, the normal biasing action of the lever arm urges the pin towards the platform until the pin slides into a corresponding notch in the platform. Because the pin is disposed on the free end of a lever arm, the pin will naturally move in a generally arcuate path towards the platform. In fact, existing swivel mechanisms position the notches about the exterior perimeter at 5 degree angles rather than directly along a radius of the platform so as to permit appropriate engagement of the lock pin therein. Unfortunately, the arcuate path of travel of the lock pin, and the necessary angled notches in the exterior perimeter of the round platform make the assemblies of the prior art substantially susceptible to disengagement at high loads. Specifically, under the new FAA test requirements, the aircraft seat is subjected to substantially higher loads in order to test the effectiveness of the engagement between the lock pin and the notch. Because of the angled orientation of the notches and the round lock pin, however, the substantial load exerted on the seat tends to urge the pin out of the notch and does not focus all of the load directly on the material construction of the pin. As such, conventional swivel designs are generally not meeting the new FAA requirements and an improved design is necessary.
Further, most conventional swivel assemblies use nylon or like material runners as a swivel surface. Such types of runners, however, do not provide for smooth motion and are susceptible to rips or rapid wear. Accordingly, such designs are often deemed undesirable because of the difficulty and expense associated with installing a replacement runner, and because of the increased friction in the swivel.
There is therefore substantial need in the related and specialized art for a swivel assembly for use in an aircraft seat which is capable of withstanding the substantial loads associated with FAA testing guidelines without premature disengagement of the assembly from a locked position. There is also a need in the art for a swivel assembly which provides for smooth and convenient swivel movement when swiveling is desired. The assembly of the present invention solves these problems.